What tube amp for Harbeth 40.1

Probably a long shot.  Anyone has experience with Luxman mq-60?  It is a vintage in 1970s.  It is a push-pull in triode mode.  It originally use 50CA10, but I am going to change it to 6L6.  It outputs 30W.  I know 30W is likely not enough, but just think to try based on the price tag.

I heard good things about atma-sphere.  But  ... it takes many tubes, it would add to the cost.  I am not sure how expensive are the tubes ... 

@squeak_king_77Thanks for your feedback on Leben.  Based on that, it seems the CS600x may not be suitable for me.  For example, compared to the Almarro and my custom built 300B, I feel the Almarro is more “linear”.  I don’t know if this is the right term.  I feel my 300B is a bit more dynamic, more engaging ... hard to tell exactly what are the differences, it is more a feeling and impression.

And my budget is $4000 for used equipments.

@twoleftears i am thinking an integrated.  It is the Z40.  Budget is a concern, bought too many gears within this year already.

@elevick yes, I considered hybrid and seriously look into McIntosh MA252.  I always want a piece of McIntosh, but have been using efficient speakers.  Initially, I think this is my chance to buy a McIntosh with 40.1.  But after doing some research, I am not sure.  MCs are expensive, and it seems a big part goes to the brand.  The MA252 is more affordable, but then some comments says it clips (with the light turns from green to orange) easily even at normal volume.  I don’t think volume is a concern for me, but it seems the quality of the product is not as good as their more expensive amps.  It seems for the money, I can get more from other brands.

Audio Reveal Second is a great match with these speakers..
 
www.highfidelity.pl/@main-990&lang=en

+1 on the recommendations for an OTL design or Line Magnetic.  You're gonna need a bit of grunt with tubes to get those Harbeths to sound lively.  I think a LM 805ia may be a good choice with its' 48w of Class A SET and 300b tubes possibly giving you exactly what you seek.

I noted J.A.'s comments when he measured the 40.1 in Stereophile:

My estimate of the big Harbeth's voltage sensitivity on its tweeter axis was 84.5dB(B)/2.83V/m, which is within experimental error of the specified 85dB/2.83V/m. This is lower than average, and suggests that a goodly powerful amplifier will be needed to achieve high playback levels. (I note that AD's 10W Shindo amplifier didn't cut it.)

Do you want integrated or power?
I was thinking this model:
https://www.lineartubeaudio.com/products/zotl-40-reference-amplifier
A lot of their products have fairly similar model numbers.
Tubes are not run anywhere near their limit and will effectively last almost indefinitely.

That is actually a question.  Does any of those amps I short listed run super hot?


I ~~~HATE~~~ SET amps, 
Why?
Extremely limited as to what speaker you can choose, not to mention to my ears they sound anemic. 
Push Pull are King of Tubes.
I havea  Defy7, has 12 6550's. I feared the heat would cook my 10x12 room, not so, 
Not sure how hot Cayin/PL run. 
I had a  small EL34 Cayin, was not hot at all,. But the bigger KT88's, , maybe. 
Your ~~super hot~~~ no I do not think either lab meets that criteria of ~~super~~
There is a pair of PL monos  on ebay starting at $1600, might not be a  bad idea throw ina  bid..But honestly I am a  bigger fan of Cayin vs PL.

All tube amps do not run hot. The LTA ZOTL amps by design generate far less heat than traditional tube amps and the tubes last far longer. They are perhaps the most practical tube amps for listeners who may be hesitant to go with tubes. In addition, the LTA amps present as much more powerful than their specs would suggest with lots of drive and dynamic capability. That said, in my experience Harbeths like power so get a ZOTL 40 Reference for now which gives you the ability to pick up a second down the road to run monos which will be plenty of juice. 

PL or cayin both Top Dawgs. 

Gte I have heard the LTA amps at shows.  The ZOTL design sounds pretty much just as advertised and related in reviews. 

All tubes run really hot, the more power the more heat dissipation.  I love Border Patrol with Harbeths but that is a lot of tubes.
You could consider a hybrid amp?  Tube for gain stage but SS output.  That will run cooler (rogue sphinx for sale here).  Class A amps are hot too.

Yes, I read good reviews on Line Magnetic especially the 219ia.  But I don’t feel comfortable with the super hot 845 tube.  One of the reason I sold my Almarro 318b is because of the heat from the 6c33c.  
That is actually a question.  Does any of those amps I short listed run super hot?

My friend has been driving his 40.2s with a Line Magnetic Audio LM-518IA. It's magical. 

@ryder Yes, I only listen to Jazz in low to medium volume averaging at 82dB.  I think a tube amp with is good for me.  My goal is to find something with more power so to improve the bass and sound, but won’t lose the 3D, holographic sound.

@mapman Do you have experience with z40?  I did some research on LTA, their ZOTL10 has very good reviews.  Their preamp got very good reviews too.  But I haven’t tried any OTL amps. I read someone said a well executed OTL gives more dynamics and lively music.  
But cost is a concern too.  The PrimaLuna are the cheapest out of the three.  

There is also a Audio Research VSI60 on sale locally for much cheaper than those three.

Were it me I would go with the LTA. 

If you don’t listen to rock or demanding music which has lots of transients and burst of dynamics, or music with a lot of deep thumping bass lines, a low to moderate powered amp would be fine. Perhaps that is the reason you find the flea-powered Almarro amp too be sufficient for the 40.1. What you need is a tube amp that is able to bring the clarity and detail from recordings at low to moderate levels, music which doesn’t have a lot of dynamic swings or demanding bass.

A friend uses the Leben CS-600 on the 40.1 and the midrange to highs show higher levels of clarity and detail. But bass does not too deep or show the same level of punch as the solid state equivalents. It depends on what you want to achieve with your system, apart from musical preference. If you want holographic or 3-dimensional sort of presentation (I like this too), do try the more powerful tube designs if possible. I know most people will say power or current is not important for Harbeth but my experience tells me otherwise. I have used many solid state amps with the Harbeth SHL5+ throughout the years.

In summary, you would do fine with flea powered tube amps with the 40.1s or any Harbeth for that matter if the music isn't too demanding or you mainly listen to mellow stuff. For wider music genres and balance, an amp that is able to provide the dynamic swings at all volume levels would be more appropriate.